Reports of potential H5N1 cases rise in Pakistan

Dec 18, 2007 (CIDRAP News) – Vigilance engendered by the possible family cluster of H5N1 avian influenza cases in Pakistan has led to many more reports of potential cases there, a World Health Organization (WHO) official said today.

Gregory Hartl, a WHO spokesman in Geneva, told CIDRAP News there have been reports of "many more potential cases due to heightened sensitivity and enhanced surveillance," though no more preliminary positive H5N1 tests have been reported.

The WHO has sent a team to investigate the situation in Pakistan, where at least eight suspected H5N1 cases, including six among relatives, have been reported in the same area. Pakistan has had a number of H5N1 outbreaks in poultry in recent months, and the suspected human cases surfaced in the wake of culling operations.

Pakistani health officials said eight people in the Peshawar area in northern Pakistan recently tested positive for H5N1 in a national lab, according to a Dec 15 WHO statement. News services have spoken of nine suspected cases, including four brothers and two of their cousins, raising concern about possible person-to-person transmission.

Hartl, commenting today by e-mail, said three WHO representatives have arrived in Peshawar and begun investigating the Pakistani cases.

He said US Navy Medical Research Unit 3 in Cairo has a portable laboratory that will arrive in Pakistan tomorrow to begin confirmatory tests of samples from the suspected cases.

More than 30 contacts of the suspected patients have been tested for H5N1 so far, with no positive results, Hartl said. Regarding testing of people with suspicious symptoms, he said, "Last one tested that I know of was on Saturday, and he tested negative."

As reported previously, the four brothers with suspected H5N1 cases have another brother who lives in New York state and went to Pakistan to attend the funeral of a brother who died. The man, who lives in Nassau County on Long Island, reported possible H5N1 exposure on his return to the United States, went into voluntary home quarantine, and was tested. The quarantine ended Dec 9, after he tested negative in a state lab and at the Centers for Disease Control and Prevention, according to a Dec 16 statement by the New York State Department of Health. The man's son, who was ill before and after the man returned home, also was tested and cleared.

Meanwhile, Indonesian officials said today they are investigating several recent human H5N1 cases in which patients had no known contact with infected birds, according to an Agence France-Presse (AFP) report.

The vast majority of human H5N1 cases have been attributed to contact with infected birds, but probable human-to-human transmission has occurred in a few cases. Increased human-to-human transmission would be regarded as the possible prelude to a pandemic.

According to AFP, Bayu Krisnamurthi, head of Indonesia's National Avian Influenza Committee, told reporters, "In the last three or four months, we have had four cases where the poultry in the victims' neighborhoods (tested) negative for the virus. The number is significant enough for us to intensify our investigations so that we could have a more accurate explanation."

Krisnamurthi said the proportion of cases involving no known contact with poultry has increased from 20% in 2006 to 30% this year, AFP reported.

Speaking at a press briefing on the avian flu situation in Indonesia, Krisnamurthi said a decrease in human cases this year signals that the country is making progress. The country has had 40 cases with 35 deaths so far this year, versus 55 cases and 45 deaths for all of last year, according to the WHO.

The WHO today noted the death of Indonesia's latest avian flu patient, a 47-year-old man from Tangerang who died Dec 13. The country's overall H5N1 count has reached 115 cases with 93 deaths.

Krisnamurthi said the agriculture ministry vaccinated 70% of Indonesia's farmed poultry against H5N1 this year, but the quality of the vaccine needs improvement, AFP reported.